Mercury fears: Robert F. Kennedy Jr. is calling for the complete removal of Thimerosal, a preservative that contains mercury, that may still be in some vaccines. [Noon, Commonwealth Club, 555 Post St., S.F.]

Fighting AIDS overseas: Dr. Yan Long sheds light on the difficulties programs designed to fight AIDS are having in China. [5 p.m., Fromm Hall, University of San Francisco, 2130 Fulton St., S.F.]

Local activities

Free museum day: The first Tuesday of the month is a free day at several museums around The City. [9:30 a.m.-5:15 p.m., De Young Museum, 55 Hagiwara Tea Garden Drive, S.F.; 9:30 a.m.-5:15 p.m., Legion of Honor, 100 34th Ave., S.F.; 11 a.m.-6 p.m., Museum of Craft and Design, 2569 Third St., S.F.]

Classic rock: Fleetwood Mac, featuring a newly returned Christine McVie, is bringing its “On With the Show” tour back to the Bay Area after selling out shows in December. [9 p.m., Oracle Arena, 7000 Coliseum Ave., S.F.]